Denji no Chichi

This unnamed man was the father of Denji. When Denji was young he killed his father in self defense, as his father was in a drunken aggressive state and he feared for his life. His father's murder was ruled a suicide by the adults in Denji’s life as acknowledging his death as a murder would mean they would be unable to get any money from his death. After his death, Denji inherits his debt to the Yakuza.